Result for: Crops: Corn for grain Corn for silage Cotton Hay Potato Rice Rye Ryegrass Sorghum Soybeans Sugar beets Sugarcane Winter wheat Wheat
4R Practices: Metadata Project

Assessing the Effects of Conservation Practices and Fertilizer Application Methods on Nitrogen and Phosphorus Loss from Farm Fields – A Meta-Analysis

Dr. Song Qian

Lead Researcher:

Dr. Song Qian

Associate Professor

University of Toledo

Start Date: 2014

End Date: 2016

Collaborating scientists and universities

  • Dr. R. Daren Harmel, USDA-ARS

Matching Funds

  • University of Toledo Research Council

Project Summary

The project augments an existing database by (1) revising studies included in the existing database to update information about fertilizer application methods, as well as additional variables, and (2) updating the database with recent studies. The project documents the use of the propensity score method and the multilevel modeling approach in the context of meta-analysis. Results are applicable for improved assessment of agricultural practices and their effects on the environment and can be used for providing realistic parameter values for watershed-scale modeling.

Project Goals:

  • Compile a large cross-sectional database to document existing studies on agriculture management practices

  • Document the use of two statistical methods for meta-analyses, as well as the effects of various conservation practices and fertilizer application methods in reducing nitrogen and phosphorus loss from farm fields.

Project Results:

  • Updated the MANAGE database and is in the process of achieving the objective of finding the effects of the two noted agricultural practices on nutrient loss.

  • Significant reductions in total phosphorus loads leaving a field when conservation practices were implemented.

  • 70 percent reduction in the amount of total phosphorus leaving a field using the 2007 version of MANAGE while current analysis of the October 2014 edition showed a 54 percent reduction in total phosphorus leaving the field.

  • The application conservation practices to a field reduce the amount of nutrient loss leaving a field.

Annual Reports